Lee described an experiment in which 50 healthy women prisoners were selected and given poisoned cabbage leaves. All of the women were required to eat the cabbage, despite cries of distress from those who had already eaten. All 50 died after 20 minutes of vomiting blood and anal bleeding. Refusing to eat the cabbage would allegedly have meant reprisals against them and their families.

Kwon Hyok, a former head of security at Camp 22, described laboratories equipped with gas chambers for suffocation gas experiments, in which three or four people, normally a family, are the experimental subjects.[6][7] After undergoing medical checks, the chambers are sealed and poison is injected through a tube, while scientists observe from above through glass. In a report reminiscent of an earlier account of a family of seven, Kwon claims to have watched one family of two parents, a son and a daughter die from suffocating gas, with the parents trying to save the children using mouth-to-mouth resuscitation for as long as they had the strength.[3]

Kwon's testimony was supported by documents from Camp 22 describing the transfer of prisoners designated for the experiments. The documents were identified as genuine by Kim Sang Hun, a London-based expert on Korea and human rights activist.[3] A press conference in Pyongyang, organized by North Korean authorities, denounced this. Japanese and Chinese media reported that the witnesses admitted to faking the documents.[8][9]

Former prison guard Ahn Myung Chul has reported that prisoners were used for "medical operation practice" by young doctors who practice surgery on prisoners without anesthesia.[10] He also described deliberate efforts to study physical resistance by starving prisoners to death. According to him, "The people who carry out these executions and these experiments all drink before they do it. But they are real experts now; sometimes they hit prisoners with a hammer, on the back of the head. The poor prisoners then lose their memory, and they use them as zombies for target practice. When the Third Bureau is running out of subjects, a black van known as "the crow" turns up and picks out a few more prisoners, sowing panic among the rest. The crow comes about once a month and takes forty or fifty people off to an unknown destination."[11]